1 /***************************************************************************
5 * Author: Randy Wells, Ohio State, rcwells@mps.ohio-state.edu
6 ***************************************************************************
8 * Description: part of STAR HBT Framework: AliFemtoMaker package
9 * This is a Coulomb correction class which
10 * 1. Reads in the dat from a file
11 * 2. Performs a linear interpolation in R and creates any array of interpolations
12 * 3. Interpolates in eta and returns the Coulomb correction to user
14 ***************************************************************************
17 * Revision 1.1.1.1 2007/03/07 10:14:49 mchojnacki
18 * First version on CVS
20 * Revision 1.17 2003/09/02 17:58:32 perev
21 * gcc 3.2 updates + WarnOff
23 * Revision 1.16 2003/02/04 21:10:31 magestro
24 * Cleaned up a couple functions
26 * Revision 1.15 2003/01/31 19:44:00 magestro
27 * Cleared up simple compiler warnings on i386_linux24
29 * Revision 1.14 2000/10/26 19:48:54 rcwells
30 * Added functionality for Coulomb correction of <qInv> in 3D correltions
32 * Revision 1.13 2000/07/16 21:38:22 laue
33 * AliFemtoCoulomb.cxx AliFemtoSectoredAnalysis.cxx : updated for standalone version
34 * AliFemtoV0.cc AliFemtoV0.h : some cast to prevent compiling warnings
35 * AliFemtoParticle.cc AliFemtoParticle.h : pointers mTrack,mV0 initialized to 0
36 * AliFemtoIOBinary.cc : some printouts in #ifdef STHBTDEBUG
37 * AliFemtoEvent.cc : B-Field set to 0.25Tesla, we have to think about a better
40 * Revision 1.12 2000/05/31 20:12:53 rcwells
41 * Modified AliFemtoCoulomb for Id and Log entries
44 **************************************************************************/
46 #include "AliFemtoCoulomb.h"
47 //#include "Stiostream.h"
50 #include "PhysicalConstants.h"
53 ClassImp(AliFemtoCoulomb)
56 AliFemtoCoulomb::AliFemtoCoulomb() {
57 fFile = "/afs/rhic/star/hbt/coul/AliFemtoCorrectionFiles/correctionpp.dat";
59 cout << " No file, dummy!" << endl;
63 fZ1Z2 = 1.0; // Default has been set up to be same sign charges
64 cout << "You have 1 default Coulomb correction!" << endl;
67 AliFemtoCoulomb::AliFemtoCoulomb(const char* readFile, const double& radius, const double& charge) {
70 CreateLookupTable(fRadius);
72 cout << "You have 1 Coulomb correction!" << endl;
75 AliFemtoCoulomb::~AliFemtoCoulomb() {
79 void AliFemtoCoulomb::SetRadius(const double& radius) {
80 cout << " AliFemtoCoulomb::setRadius() " << endl;
82 CreateLookupTable(fRadius);
85 double AliFemtoCoulomb::GetRadius() {
89 void AliFemtoCoulomb::SetFile(const char* readFile) {
90 cout << " AliFemtoCoulomb::SetFile() " << endl;
92 // Create new lookup table since file has changed
94 CreateLookupTable(fRadius);
98 void AliFemtoCoulomb::SetChargeProduct(const double& charge) {
99 cout << " AliFemtoCoulomb::SetChargeProduct() " << endl;
100 if ( fZ1Z2!=charge ) {
103 fFile = "/afs/rhic/star/hbt/coul/AliFemtoCorrectionFiles/correctionpp.dat";
106 fFile = "/afs/rhic/star/hbt/coul/AliFemtoCorrectionFiles/correctionpm.dat";
108 CreateLookupTable(fRadius);
112 void AliFemtoCoulomb::CreateLookupTable(const double& radius) {
113 cout << " AliFemtoCoulomb::CreateLookupTable() " << endl;
114 // Read radii from fFile
115 // Create array(pair) of linear interpolation between radii
118 cout << " AliFemtoCoulomb::CreateLookupTable -> NEGATIVE RADIUS " << endl;
119 cout << " call AliFemtoCoulomb::SetRadius(r) with positive r " << endl;
120 cerr << " AliFemtoCoulomb::CreateLookupTable -> NEGATIVE RADIUS " << endl;
121 cerr << " call AliFemtoCoulomb::SetRadius(r) with positive r " << endl;
124 ifstream mystream(fFile);
126 cout << "Could not open file" << endl;
130 cout << "Input correction file opened" << endl;
133 static char tempstring[2001];
134 static float radii[2000];
135 static int NRadii = 0;
137 if (!mystream.getline(tempstring,2000)) {
138 cout << "Could not read radii from file" << endl;
141 for (unsigned int ii=0; ii<strlen(tempstring); ii++) {
142 while (tempstring[ii]==' ') ii++;
143 sscanf(&tempstring[ii++],"%f",&radii[++NRadii]);
144 while ( tempstring[ii]!=' ' && (ii)<strlen(tempstring) )ii++;
146 cout << " Read " << NRadii << " radii from file" << endl;
148 static double LowRadius = -1.0;
149 static double HighRadius = -1.0;
150 static int LowIndex = 0;
154 for(int iii=1; iii<=NRadii-1; iii++) { // Loop to one less than #radii
155 if ( radius >= radii[iii] && radius <= radii[iii+1] ) {
156 LowRadius = radii[iii];
157 HighRadius = radii[iii+1];
161 if ( (LowRadius < 0.0) || (HighRadius < 0.0) ) {
162 cout << "AliFemtoCoulomb::CreateLookupTable --> Problem interpolating radius" << endl;
163 cout << " Check range of radii in lookup file...." << endl;
164 cerr << "AliFemtoCoulomb::CreateLookupTable --> Problem interpolating radius" << endl;
165 cerr << " Check range of radii in lookup file...." << endl;
169 static double corr[100]; // array of corrections ... must be > NRadii
171 static double tempEta = 0;
173 while (mystream >> tempEta) {
174 for (int i=1; i<=NRadii; i++) {
177 static double LowCoulomb = 0;
178 static double HighCoulomb = 0;
179 static double nCorr = 0;
180 LowCoulomb = corr[LowIndex];
181 HighCoulomb = corr[LowIndex+1];
182 nCorr = ( (radius-LowRadius)*HighCoulomb+(HighRadius-radius)*LowCoulomb )/(HighRadius-LowRadius);
183 fEta[fNLines] = tempEta; // Eta
184 fCoulomb[fNLines] = nCorr; // Interpolated Coulomb correction for radius
188 cout << "Lookup Table is created with " << fNLines << " points" << endl;
191 double AliFemtoCoulomb::CoulombCorrect(const double& eta) {
192 // Interpolates in eta
194 cout << "AliFemtoCoulomb::CoulombCorrect(eta) --> Trying to correct for negative radius!" << endl;
195 cerr << "AliFemtoCoulomb::CoulombCorrect(eta) --> Trying to correct for negative radius!" << endl;
199 middle=int( (fNLines-1)/2 );
200 if (eta*fEta[middle]<0.0) {
201 cout << "AliFemtoCoulomb::CoulombCorrect(eta) --> eta: " << eta << " has wrong sign for data file! " << endl;
202 cerr << "AliFemtoCoulomb::CoulombCorrect(eta) --> eta: " << eta << " has wrong sign for data file! " << endl;
206 static double Corr = 0;
209 if ( (eta>fEta[0]) && (fEta[0]>0.0) ) {
213 if ( (eta<fEta[fNLines-1]) && (fEta[fNLines-1]<0.0) ) {
214 Corr = fCoulomb[fNLines-1];
217 // This is a binary search for the bracketing pair of data points
220 static int width = 0;
224 middle = int(width/2.0); // Was instantiated above
226 if (fEta[low+middle] < eta) {
227 // eta is in the 1st half
230 middle = int(width/2.0);
233 // eta is in the 2nd half
236 middle = int(width/2.0);
239 // Make sure we found the right one
240 if ( (fEta[low] >= eta) && (eta >= fEta[low+1]) ) {
241 static double LowEta = 0;
242 static double HighEta = 0;
243 static double LowCoulomb = 0;
244 static double HighCoulomb = 0;
246 HighEta = fEta[low+1];
247 LowCoulomb = fCoulomb[low];
248 HighCoulomb = fCoulomb[low+1];
249 // cout << LowEta << " *** Eta *** " << HighEta << endl;
250 // cout << LowCoulomb << " *** Coulomb *** " << HighCoulomb << endl;
251 Corr = ( (eta-LowEta)*HighCoulomb+(HighEta-eta)*LowCoulomb )/(HighEta-LowEta);
254 cout << "AliFemtoCoulomb::CoulombCorrect(eta) --> No correction" << endl;
255 cout << " Check range of eta in file: Input eta " << eta << endl;
256 cerr << "AliFemtoCoulomb::CoulombCorrect(eta) --> No correction" << endl;
257 cerr << " Check range of eta in file: Input eta " << eta << endl;
264 double AliFemtoCoulomb::CoulombCorrect(const double& eta,
265 const double& radius) {
266 // Checks radii ... input radius and fRadius
267 // Calls createLookupTable if neccessary
268 // Interpolate(linear) between etas in the created lookup table
272 // Both radii are negative
273 cout << "AliFemtoCoulomb::CoulombCorrect(eta,r) --> input and member radii are negative!" << endl;
274 cerr << "AliFemtoCoulomb::CoulombCorrect(eta,r) --> input and member radii are negative!" << endl;
280 if (radius == fRadius) {
281 // Both radii are positive and equal
282 // cout << "Radii are the same!!!" << endl;
285 // Both radii are positive but not equal
287 CreateLookupTable(fRadius);
291 // Interpolate in eta
292 return ( CoulombCorrect(eta) );
295 double AliFemtoCoulomb::CoulombCorrect(const AliFemtoPair* pair) {
296 return ( CoulombCorrect( Eta(pair) ) );;
299 double AliFemtoCoulomb::CoulombCorrect(const AliFemtoPair* pair, const double& radius) {
300 return ( CoulombCorrect( Eta(pair),radius ) );
303 double AliFemtoCoulomb::Eta(const AliFemtoPair* pair) {
304 static double px1,py1,pz1,px2,py2,pz2;
305 static double px1new,py1new,pz1new;
306 static double px2new,py2new,pz2new;
307 static double vx1cms,vy1cms,vz1cms;
308 static double vx2cms,vy2cms,vz2cms;
309 static double VcmsX,VcmsY,VcmsZ;
310 static double dv = 0.0;
311 static double e1,e2,e1new,e2new;
312 static double psi,theta;
313 static double beta,gamma;
314 static double VcmsXnew;
316 px1 = pair->track1()->FourMomentum().px();
317 py1 = pair->track1()->FourMomentum().py();
318 pz1 = pair->track1()->FourMomentum().pz();
319 e1 = pair->track1()->FourMomentum().e();
320 px2 = pair->track2()->FourMomentum().px();
321 py2 = pair->track2()->FourMomentum().py();
322 pz2 = pair->track2()->FourMomentum().pz();
323 e2 = pair->track2()->FourMomentum().e();
325 VcmsX = ( px1+px2 )/( e1+e2 );
326 VcmsY = ( py1+py2 )/( e1+e2 );
327 VcmsZ = ( pz1+pz2 )/( e1+e2 );
328 // Rotate Vcms to x-direction
329 psi = atan(VcmsY/VcmsX);
330 VcmsXnew = VcmsX*cos(psi)+VcmsY*sin(psi);
332 theta = atan(VcmsZ/VcmsX);
333 VcmsXnew = VcmsX*cos(theta)+VcmsZ*sin(theta);
337 gamma = 1.0/::sqrt( 1.0-beta*beta );
339 // Rotate p1 and p2 to new frame
340 px1new = px1*cos(psi)+py1*sin(psi);
341 py1new = -px1*sin(psi)+py1*cos(psi);
343 px1new = px1*cos(theta)+pz1*sin(theta);
344 pz1new = -px1*sin(theta)+pz1*cos(theta);
349 px2new = px2*cos(psi)+py2*sin(psi);
350 py2new = -px2*sin(psi)+py2*cos(psi);
352 px2new = px2*cos(theta)+pz2*sin(theta);
353 pz2new = -px2*sin(theta)+pz2*cos(theta);
358 // Lorentz transform the x component and energy
359 e1new = gamma*e1 - gamma*beta*px1;
360 px1new = -gamma*beta*e1 + gamma*px1;
361 e2new = gamma*e2 - gamma*beta*px2;
362 px2new = -gamma*beta*e2 + gamma*px2;
374 // Velocity difference in CMS frame
375 dv = ::sqrt( (vx1cms-vx2cms)*(vx1cms-vx2cms) +
376 (vy1cms-vy2cms)*(vy1cms-vy2cms) +
377 (vz1cms-vz2cms)*(vz1cms-vz2cms) );
379 return ( fZ1Z2*fine_structure_const/(dv) );
382 TH1D* AliFemtoCoulomb::CorrectionHistogram(const double& mass1, const double& mass2, const int& nBins,
383 const double& low, const double& high) {
384 if ( mass1!=mass2 ) {
385 cout << "Masses not equal ... try again. No histogram created." << endl;
388 TH1D* correction = new TH1D("correction","Coulomb correction",nBins,low,high);
389 const double reducedMass = mass1*mass2/(mass1+mass2);
391 //double dQinv = (high-low)/( (double)nBins );
393 for (int ii=1; ii<=nBins; ii++)
395 qInv = correction->GetBinCenter(ii);
396 eta = 2.0*fZ1Z2*reducedMass*fine_structure_const/( qInv );
397 CoulombCorrect( eta );
398 correction->Fill( qInv, CoulombCorrect(eta,fRadius) );
405 TH1D* AliFemtoCoulomb::CorrectionHistogram(const TH1D* histo, const double mass) {
407 TH1D* correction = (TH1D*) ((TH1D*)histo)->Clone();
409 correction->SetDirectory(0);
410 int nBins = correction->GetXaxis()->GetNbins();
411 const double reducedMass = 0.5*mass;
414 for (int ii=1; ii<=nBins; ii++)
416 qInv = correction->GetBinCenter(ii);
417 eta = 2.0*fZ1Z2*reducedMass*fine_structure_const/( qInv );
418 correction->Fill( qInv, CoulombCorrect(eta,fRadius) );
424 TH3D* AliFemtoCoulomb::CorrectionHistogram(const TH3D* histo, const double mass) {
426 TH3D* correction = (TH3D*) ((TH3D*)histo)->Clone();
428 correction->SetDirectory(0);
429 int nBinsX = correction->GetXaxis()->GetNbins();
430 int nBinsY = correction->GetYaxis()->GetNbins();
431 int nBinsZ = correction->GetZaxis()->GetNbins();
432 const double reducedMass = 0.5*mass;
436 for (int ii=1; ii<=nBinsX; ii++) {
437 for (int iii=1; iii<=nBinsY; iii++) {
438 for (int iv=1; iv<=nBinsZ; iv++) {
439 binNumber = histo->GetBin(ii,iii,iv);
440 qInv = histo->GetBinContent(binNumber);
441 eta = 2.0*fZ1Z2*reducedMass*fine_structure_const/( qInv );
442 correction->SetBinContent(binNumber, CoulombCorrect(eta,fRadius) );
450 double AliFemtoCoulomb::CoulombCorrect(const double& mass, const double& charge,
451 const double& radius, const double& qInv) {
454 const double reducedMass = 0.5*mass; // must be same mass particles
455 double eta = 2.0*fZ1Z2*reducedMass*fine_structure_const/( qInv );
456 return ( CoulombCorrect(eta,fRadius) );